RepliKate
by HotChilliGriffin
Summary: Just what the title says. Scific.
1. Chapter 1

**RepliKate, chapter one**

Mike stared at the sight in front of him. He opened his mouth as if to say something, then closed it. He cast a pleading glance around the bridge, but the crew wouldn't meet his eyes. He had to deal with it himself.

"I officially declare this to be the weirdest thing that has ever happened in my career," he muttered.

Kate nodded.

Kate frowned.

At that movement, Mike's expression changed from pained to desperate.

"Someone please tell me this is a joke," he begged.

"No-one told me about one," Kate said, glaring.

"Who the hell _are_ you?" Kate asked, also glaring. "And why... do you... _look_ like me?"

"No, I'm me," Kate growled. She was about to continue, but Mike held up one hand.

"Calm down," he ordered. His gaze flickered between the two women. "_Both_ of you."

"I'm perfectly calm," Kate sniffed. "Absolutely. Totally... dear God what's going on?"

Charge, resting on the table behind the CO, suddenly spoke up.

"We should check that they both are... you know, who they say they are."

"One of them isn't," Buffer pointed out.

"I _hope_ one of them isn't," Mike muttered, then turned to the two women in front of him. "I'm going to ask you some questions. You answer at the same time. Got it?"

The nodded. "Name? Whole name," asked Mike.

"Kaitlin Alexandra McGregor," the two Kates chimed, and then glared at one another again.

"Date of birth?"

"Twenty-first of June, Nineteen-eighty," they said together.

"Address?"

"Sixteen, Dumont road."

"Rank and position?" called Buffer.

"Lieutenant, XO."

Swain held up two fingers.

"Number of fingers?" he asked. One Kate answered correctly, the other merely rolled her eyes.

"There are two of us, we're not concussed," she growled.

Mike dragged a hand across his face, then resumed staring at the two women.

"They're identical," he muttered.

"Are they?" asked Swain. "I mean, there's got to be a difference."

"The one on the right has longer hair," Buffer pointed out. The Kate in question looked momentarily taken aback.

"I do not!" she protested a second later.

"That wasn't an insult, just a fact," Mike said, sighing, realising that one Kate did indeed have longer hair; her plait – twisted together in normal Kate-fashion – extended approximately three centimetres further down her back. The other Kate looked slightly miffed by this revelation.

"But how long is it _supposed_ to be?" Swain asked. Mike shot him a look, clearly telling him not to go there.

For a minute, there was silence, then Charge spoke up.

"One at a time, I want both of you to talk us through your day," he suggested. Before either of them could say anything, he quickly pointed at the Kate with shorter hair. "You first."

"I woke up, had a shower and got dressed, came here," she said, the faintest trace of sarcasm underneath her words. The second Kate angled her thumb towards the first.

"Same."

"If they've got the same address..."

"One of them is lying," Mike said. The two Kates glared at him, and he shrugged helplessly. "Anyone have any other rational explanations?"

"Hole in the space time continuum?" Swain suggested.

"I said _rational_," Mike said. There was a pause.

"Parallel universe?"

"That's it," Mike muttered. "I'm calling Marshall."


	2. Chapter 2

**RepliKate, chapter Two**

When Marshall arrived at the dock, Mike was waiting for him.

"This better be important," Marshall grumbled. "The Kingston are close to capturing an iceboat, and I've got –"

"Wait until you see what we've got," Mike muttered, adding, "Sir," as an afterthought.

The two of them stepped onto the Hammersley's gangplank, and saluted. Waiting at the other end were the two Kates, and both straightened slightly and saluted Marshall as he came aboard.

He stared at them for a moment, before his eyes narrowed. "Is this a joke?" he growled.

"I hope so," Mike replied, sighing. "But so far, it appears not."

"You have two XOs."

"Yes, sir."

"You have... _two_ Kate McGregors?"

"Yes, sir."

"Yes, sir!" the two Kates said together, sarcasm evident. They then snorted at the unplanned chorus.

Marshall sighed. "I'm guessing you checked that one of them isn't an imposter?"

"We tried," Mike agreed. "They know everything about themselves. They really do seem to be the same person. Twice."

"Except her hair is too long," one Kate said, nodding towards the other's plait.

Marshall seemed lost for words. No-one said anything, as they could see he was thinking hard about the situation.

"What exactly did you ask them?" he eventually questioned.

"Name, address, date of birth, rank..."

"Did anyone consider cloning?" one Kate interrupted.

The other rolled her eyes. "And that would _really_ explain everything."

"It might. The clone wouldn't have a belly button, so it's easy to prove."

"No belly button?" Kate paused, then glanced around. "She even likes the Simpsons. That's scary."

"Can we get on track?" Mike asked. Seeing the strain the situation was having on him, the two Kates stopped talking. They were finding, oddly enough, that their opposite was very good conversation.

Marshall turned to the pair. "What date is it?"

"September twenty-second," they replied.

Marshall paused before asking, "Year?"

One Kate snorted, and didn't answer. The other rolled her eyes.

"Twenty-oh-nine."

There was silence, as everyone stared at her. She fidgeted slightly. "What?"

"Explains why her hair is longer," the other Kate said, a distinct look of unease on her face.

"It's two thousand and eight," Mike said. The second Kate frowned.

"No... it's not... hang on." She looked around, as if waiting for someone to call, 'Psyche!'. No-one did. She swallowed. "It's... that's not right."

"That's not good."

"Kate, calm down," Mike said, and both women looked up, then at each other.

"Who's he talking to?" one asked, and the other shrugged. Mike sighed.

"Right, first I think we should rename one of you." He pointed at the Kate with shorter hair. "You stay as Kate." He then pointed at the other Kate. "You're Kaitlin."

She frowned. "I hate that name," she muttered.

"How about she's Kate, and I'm X?" the other Kate suggested.

Marshall nodded. "Alright. Now, the question remains – what is going on?"

Kate shrugged. "I got up this morning and came here. Last night was definitely 2009. And you're saying today is..."

"The same day, one year earlier."

"So... it's not Tuesday?" Kate checked.

X shook her head. "Nope, Monday."

"Dear Lord... what did I do?"

"New twist on the saying, waking up on the wrong side of bed," Marshall muttered to Mike. His gaze returned to Kate, and he continued trying to evaluate her.

"What's that?" he asked, pointing to a scar on her right arm – a scar that X didn't have. Kate frowned, obviously slightly put out that no-one remembered what had happened.

"It was a boarding, got nicked by a machete. About eight months back." She considered. "That would be four months from now."

X swallowed. "Note to self..." she murmured. Kate suddenly looked shocked.

"I probably shouldn't have told you that..." she muttered. "In fact, I'm going to stop talking, now, before I destroy the space time continuum."

Marshall's phone suddenly rang, and he backed away, answering it. X and Kate exchanged glances.

"Are you _sure_ this is '08?" Kate asked. "How do you know it's not you guys who magically appeared in my time zone?"

"I think this goes _way_ beyond time zones," Mike muttered.

"There's several dozen of us," X replied, gesturing at the boat and nearby street, "and one of you."

"No, there's two of me," Kate replied.

"_You_ shouldn't be here at all!" X growled.

"You know, I didn't _ask_ to come here," Kate snapped. "The universe is doing something crazy, and I don't like it much more than any of you."

Nearby, Marshall lowered his phone, and rubbed at his forehead. The trio on deck looked over at him.

"Mike, we've got a pair of suspected FFVs halfway between here and the border. Coastwatch spotted them. They obviously came much further than they intended, and are now making for the border."

Pained, his glance passed over the two Kates before continuing. "If you leave now, you can probably catch them."

"Uh, s-sir?" Mike stuttered. "I think this is a bigger problem..."

Marshall shrugged absently. "It can wait. As far as I can tell, she's not going anywhere. You've got an extra crewmember. Now, I've got another problem back at Navcom, I'll talk to you later."

Looking as though he would collapse from the strain his mind was being placed under, Marshall wandered up the gangplank and back towards his car. Grimacing, Mike turned back to the two women.

"So, uh... how do we tell the crew?" he asked. So far, only Buffer, Swain and Charge knew, as they'd been the only ones in the bridge when two Kates had turned up. Now, the pair looked at each other.

"We'll leave you to explain that," X said, smiling sweetly, and with a sigh, Mike led the way to the bridge.


	3. Chapter 3

**RepliKate, chapter Three**

"Nikki," X called, and Nav smiled innocently. X rolled her eyes. "Stop staring."

"I'm not," the brunette protested, her eyes sliding sideways the second Kate.

"Two against one says you're staring," Kate murmured, and X snorted.

"Do we count as two on one?" she asked.

"I think so. Do you think we could pull of a duet?"

"I can't sing," X said, and Kate smirked.

"I can."

X frowned. "Sometime in the next year, I take singing lessons?"

Kate suddenly looked uneasy. "See, this is why I shouldn't be saying things..." X glared at her, and Kate bit her lip. "Fine. About six months ago, I went out with a guy who was a singing teacher... it was fun."

"Does it last?" X asked, curious. Kate sighed.

"No, but it was good. And nothing else. How do you even know you _want_ to know what's going to happen..."

"You know they say talking to yourself is the first sign of madness," Nikki broke in cheekily. They glanced at her, the movement perfectly coordinated. She shook her head in amazement, and continued staring.

"You know, we're of higher rank than her, so we could probably kick her out of our – my – this cabin," X suggested, glancing at her future self. Nikki gulped. Kate considered.

"Actually... considering I technically have more experience than you... I could probably kick you out."

X straightened up, looking herself in the eye. "But this is _my_ time zone. You popped into _my_ life. And I damn well want to pop _you_ – that is, me – back to 2009."

Before the argument could continue, Nikki stood up, looking unnerved. "I think I have to go to the bridge now," she muttered, and left. Kate stared after her.

"I think we're a little scary," she mused. X nodded.

"So it would seem..."

"Did you ever watch that movie, Freaky Friday? Wait, stupid question."

"This is just a little freakier."

"And it's Tuesday."

"Monday," X corrected, and Kate rolled her eyes.

There was a pause, and then they both spoke at the same time. "I'm hungry."

Surprised, they shared a look.

"We're... we're kind of the same person, so I guess that makes sense..." X said slowly.

"We _are_ the same person, aren't we..." mused Kate. "But we're kind of... not."

"Want to head down to the galley?" suggested X, and Kate nodded.

***

Bomber carefully lowered a hot tray into place, wiped her hands on a towel, turned around, and jumped backwards in surprise. The two Kates smiled slightly.

"Don't _do_ that," Bomber growled, eying them suspiciously. By now the whole crew had accepted the impossible – Kate had travelled through time. Bomber especially had been warned, considering that she would be cooking lunch for one extra.

There were footsteps down the hall, the heavy tread prophesising Buffer's approach. His gaze flickered over the two women getting themselves lunch, and then over the expression on Bomber's face. His lips twitched with the vestiges of a smile, as he greeted each of them with a nod.

"Looks like we weren't in time to avoid the lunch rush," sighed Kate, moving aside as Swain arrived, Spider hot on his heels.

The young seamen took one look at the two Kates, and swallowed, his face white.

"Hi," he squeaked, regaining a little of his composure when he realised that Swain was just suppressing a chuckle and Buff was out-right laughing. To change the focus of the room, Swain turned to the pair, trying to work out which one was which.

"We need to give you nametags," he muttered. "You're like twins. Only... worse."

"Which one's the evil twin, then?" Buffer asked, still smiling broadly.

"Her," they both answered, pointing at each other. X raised one hand.

"I'm the normal one, who doesn't travel through time," she announced. Ignoring Kate's murmur of, '_Not yet'_, she added, "Call me X, call her Kate."

Holding himself upright against the wall, Spider nodded nervously. Kate smirked. Swain turned to her.

"So, um, Kate... do you know what Chloe's first word is?"

Kate rolled her eyes. "What happened to not destroying the universe?" she asked innocently.

Swain shrugged. "So..."

"So wait and see," Kate replied, rolling her eyes.

"He's got a point. Anything happen this year we should know about?" Bomber asked, raising her eyebrows hopefully.

"No, not really..." Kate said uncomfortably. "I really don't think I should be saying anything... because if something changes, then I could cease to exist... or someone else could cease to exist..."

"And if _you_ don't exist... then you never come back, never change anything, so you _do_ exist... so the universe ends. Fascinating."

The group around the galley turned to see RO coming down the hall. He seemed mostly uninterested in the abnormality standing to one side. Spider stared at him, wondering how he could look so calm. RO caught the look, and snorted.

"If you don't mind, some of us want lunch," he snapped, flashing a quick smile at Bomber before departing.

"He's right, though," Kate muttered. "I've never had the fate of the entire universe on my shoulders before."

"If something could happen, wouldn't you just being here cause it?" Bomber asked. Swain nodded eagerly in agreement.

"Or," Buffer began, drawing out the word, "What you do here could be what causes the universe to remain intact. By _not_ doing something –"

"I think we've all freaked me out quite enough, now," X said, holding up a hand. The hallway was very cramped considering the number of people all hanging outside the galley, and she rolled her eyes.

"We can discuss the future of the universe somewhere else," she proclaimed, and started shooing the group away.

***

"XO, to the bridge," called Mike over the internal radio. Both Kates stood up, and X smirked.

"He means me," she pointed out. Kate frowned.

"That's _both_ of you," Mike elaborated, X rolled her eyes, leading the way upstairs.

"Found the FFVs, sir?" X asked. He nodded, tried not to wince when he turned around, and failed. He swallowed nervously, and before he even spoke the words, everyone in the bridge knew what he was going to say.

"X, I'm going to get Buffer to lead this one," he said quickly, knowing from previous experience her reaction.

"What?" X asked, her eyes blazing. "Why?"

"All of this must be very confusing for you... and you're distracted right now, and in my professional opinion, I don't think..."

"Are you serious?" Kate asked, glaring at him. "You have _two_ XOs, and you're not going to use _either_ of them?"

Mike nodded, his gaze flicking between them. "Can one of you... change shirts or something?" he asked.

Kate scowled. "Stop changing the subject, and give me my boarding party."

"Excuse me? I believe it's _my_ boarding party," X spluttered.

Mike sighed, and brought a hand up to his temples. "I don't think it's appropriate to be having this conversation. Buffer is completely capable. And you two... are a distraction at the very least."

"Two against one," Kate challenged. From her console, Nav rolled her eyes.

Mike gazed at her sadly. "You're future Kate?" he checked, and she nodded, smirking. "I cannot believe that a year from now you're as stubborn as ever."

Mike stepped away. "You both stay here. We nab these fisherman, then go home and try to save the world."

Scowling, they could hear in his tone that the subject was no longer open for negotiation, and with a final forlorn glance outside at the two shoddy looking boats, headed downstairs.

X suddenly had a thought, and turned to herself.

"What _is_ Chloe's first word?"

Kate rolled her eyes. "It's _na-na_. She's trying to say banana, as far as we could tell. And, lucky us, Swain doesn't stop talking about it for the next month."


	4. Chapter 4

**RepliKate, chapter Four**

"I want to wake up tomorrow and have everything back to normal," Kate groaned, flopping back onto the rack beside her. X sighed, nodding, and then narrowed her eyes.

"You're in my rack," she pointed out, crossing her arms as threateningly as possible.

Kate snickered slightly. "You can't pull off that posture with me," she said, slightly amused. "Because I know the thought process behind it. You're too tired to argue, and there is no way you would actually do anything if I didn't do what you said."

X's arms dropped. "Damn you. Damn _me_."

"Damn universe," they chimed.

"You know, in hindsight, maybe one of us – that is, you – should have run off to Bomber's cabin."

"I reckon Nav wanted out," Kate replied, shrugging. "I probably would have, too, in her position."

"Yes, who'd want to share a cabin with Duplico..." There was a pause, then X continued. "Now, get off my rack."

"Mine."

"No."

"Yes. Seniority means better rack, remember?"

"You are _not_ my senior."

The two glared at one another for a few minutes, before the same thought struck them both at the same time. They didn't bother saying it out loud. They were as stubborn as each other, and there was no point in a glaring contest – they would tie every time.

"If you've got a problem with it, blame the universe. I wasn't _trying _to fall back a year," Kate snapped.

Without another word, X left the cabin.

***

Mike was on watch in the bridge when he heard the door behind him swing open. He glanced behind him. It was Kate – well, one of them. He opened his mouth to greet her, then hesitated.

"X," she supplied, and he nodded.

"How's it going?" he asked.

"We have a problem," she growled.

"A new one?"

"No, the same one. One _eensy weensy_ little problem." Mike raised an eyebrow, leading her to scowl. "There's two of me."

"We'll be home tomorrow," he said. "And then we'll sort something out."

"How do you plan on _sorting it out_?" X asked incredulously. "Throw her – me – back through the hole she/I fell through?"

He pretended to consider. Then his expression cleared.

"It's the space time continuum we're dealing with, right?" She nodded. "And who knows a lot about that particular subject?"

X frowned, thinking though everyone she knew. "RO?" she asked tentatively.

He rolled his eyes. "What about Stephen Hawking?"

"I think it was Einstein who worked on the space-time continuum..."

"Yes, but Einstein is dead."

He opened his mouth to continue, but stopped when he saw the look in her eye.

"I have to stand up for myself here," she said sternly. "We are not a sideshow. You are not calling in every newspaper and scientist in the country to –"

"I wasn't suggesting that," he cut her off, frowning. "You said yourself, we have a problem. I'm taking all the necessary steps to fix it."

She glared. "I kicked me out of my rack."

"There are _two_ racks in your cabin."

"Why should she get the better one?"

"X, I hate to be the one to break this to you, but neither rack is better than the other. You just don't like being up top. And why _shouldn't_ she get the bottom one?"

"It's my rack," she grumbled, suddenly realising she was fighting a losing battle. This was confirmed when he raised an eyebrow.

"It's hers, too."

Without another word, X turned and left the bridge. Mike stared after her for a few minutes. He knew Marshall was doing everything he could not to let this _event_ become a media circus, but what if that wasn't good enough?

***

As herself came through the cabin door, Kate smirked.

"That's odd," she said sweetly. "The CO didn't rush down after you demanding that I give you your rack back."

X scowled, pulled herself up to the top rack, flipped off the light, and instantly felt uncomfortable. She closed her eyes, but then they snapped open. She could practically feel the distance between her and the floor. She shifted closer to the wall, and tried to relax.

Her thoughts inevitable strayed to the captain. She instantly smacked away the image of his grey eyes shining in the late night light. That would _not_ help her relax.

"Answer me one question, just one, then I'll stop asking," she called, and Kate gave a grunt of agreement. "The CO."

"Mike."

"The CO."

"Yes."

"What do you mean, 'yes'? You don't know what I was going to ask."

Kate smiled to herself. "Yes I do. And yes, you do."

"I do what?"

"You know what," Kate said, thoroughly enjoying herself.

Sighing loudly, X stopped asking – she did know what. "Damn it," she whispered. Then, louder, she asked, "When?"

"Uh... from _now_... maybe a month?"

X's second curse was slightly louder. Kate rolled her eyes. "And that's all the fortune telling you're going to get."

***

When X woke in the morning, there was a single moment of brilliant hope. The rack below her was empty. Had her future-self been snapped back to her own time? She jumped down, pulled her overalls up around her shoulders, tucked her loose blonde hair back behind her ears, and set off down the corridor.

It didn't take her long to realise Kate was in the senior sailors mess, eating breakfast with Buffer and Mike. Her hair was already bound in a tight braid, and X began to wish she'd fixed hers before leaving her cabin. At her entrance, the three before her all looked up and nodded a good morning.

"Sleep well?" Mike teased, and X's eyes narrowed slightly.

"Unfortunately, the sudden appearance of my future self was not a dream."

"Unfortunately, my sudden appearance in the wrong _year_ wasn't a dream," Kate added.

"You were right, sir," X said, glancing at Mike. "She _is_ as stubborn as me."

"More so," Buffer pointed out. When they all looked at him, he shrugged. "Who got the better bunk last night?"

For a moment, Kate wasn't sure whether to be proud or insulted by the observation. Before she could make up her mind, Mike was speaking.

"I told them my plan," he said to X. She raised one eyebrow.

"This is the same plan you were telling me about last night?" she asked, and he nodded. She carefully controlled her expression. "Sir, that's a pretty stupid plan."

"I reckon it's worth a shot," Buffer said, nodding slightly.

"So do I," Kate agreed, and X cocked her head curiously.

"What happened to us agreeing to everything?"

Kate shrugged. "I think it'll work."

Mike smiled at her. "Well, I've got one vote of confidence."

"I think it will work because it already did."

The three around her waited for her to elaborate. Realising none of them had figured out what she had, Kate continued.

"One year ago, I was standing there, having this discussion," she said, pointing towards X. "One year ago, _my_ future self popped back here and –"

"Do you remember that?" X interrupted, and Kate paused.

"No. Maybe whatever we did to _fix_ the loop meant it only happened once, and so each time it's new."

"If it was only happening once, it wouldn't be a loop," Buffer pointed out.

Kate considered. "Okay, well, maybe it only happens in my mind – this version of me – in each loop."

X considered. "Or maybe this is first time that the loop has happened –"

"Where does a circle start? You can't have the first run through of a loop, it contradicts the very definition," Buffer said. So far, on the topic of loops, the captain had been silent, however he lifted his head at Buffer's words.

"Where does a square begin?" he asked.

Seeing that the entire conversation was about to devolve into a theoretical discussion about improperly coded loops, X intervened. "Either way, in _this_ universe or loop or broken timeline, we have to somehow set everything right."

"Good point, X. We'll be in port in approximately two hours." Mike stood up, ready to take his empty bowl back to the galley. "And X? Today, you're not to plait your hair."


End file.
